Machine and method for manipulating shredded tobacco

ABSTRACT

A method and machine for manipulating tobacco having a pneumatic system arranged to feed shredded tobacco upwardly on to the underside of a foraminous conveyor belt mounted below and adjacent to a horizontally elongated suction chamber in order to form a filler stream thereon which is later formed into a wrapped cigarette rod and cut into individual cigarettes. Tobacco is fed to the conveyor in excess of that required in the rod and the excess is removed by trimming in order to obtain uniformity in the rod. Inevitable variations in uniformity in the filler are reduced by controlling the degree of pneumatic compaction of the same by means of detectors which are arranged to manipulate a throttling or needle valve for controlling the degree of suction in the suction chamber thereby controlling the quantity of tobacco remaining between the trimming device and the conveyor and reducing variations in the filler when and if they should occur.

United States Patent 1 Pocock 1 May8,1973

[54] MACHINE AND METHOD FOR MANIPULATING SHREDDED TOBACCO [75] Inventor:Frederick Pocock, Deptford, Lon- 211 App]. No.: 108,792

[30] Foreign Application Priority Data May 10, 1960 Great Britain..l6,460/60 [52] US. Cl ..l31/21 B, 131/21 D, 131/84 B, 131/84 C [51]Int. Cl ..A24c 05/34 [58] Field of Search ..13l/21 B, 84,110, 131/21, 21A, 84 B, 84 C; 19/70, 239, 240; 250/834 [56] References Cited UNITEDSTATES PATENTS 3,089,497 5/1963 Molins et al. ..l3l/84 C X 2,660,17811/1953 Rault 3,039,473 6/1962 Schubert ..131/84 C 2,162,443 6/1939Muller ..13l/2l A 2,516,932 8/1950 Wainwright ..l3l/2l B 2,938,5215/1960 Lanore l3l/2l B 2,465,818 3/1949 Richardson 1 9/70 2,843,8827/1958 Lewis et a]. ..19/70 2,981,986 5/1961 Neil ..l9/70 2,407,1009/1946 Richardson ..l9/70 2,952,262 9/1960 Pecock et a1 ..l3 1/21 EFOREIGN PATENTS OR APPLICATIONS 385,946 2/1933 Great Britain..; ..l3l/21A Primary Examiner-Joseph S. Reich AttorneyFrancis G. Cole [57] ABSTRACTA method and machine for manipulating tobacco having a pneumatic systemarranged to feed shredded tobacco upwardly on to the underside of aforaminous conveyor belt mounted below and adjacent to a horizontallyelongated suction chamber in order to form a filler stream thereon whichis later formed into a wrapped cigarette rod and cut into individualcigarettes. Tobacco is fed to the conveyor in excess of that required inthe rod and the excess is removed by trimming in order to obtainuniformity in the rod. lnevitable variations in uniformity in the fillerare reduced by controlling the degree of pneumatic compaction of thesame by means of detectors which are arranged to manipulate a throttlingor needle valve for controlling the degree of suction in the suctionchamber thereby controlling the quantity of tobacco remaining betweenthe trimming device and the conveyor and reducing variations in thefiller when and if they should occur.

4 Claims, 6 Drawing Figures PATENTEDHAY 81973 SHEET 3 OF 5 g azmwAT-romvsyg PATENTEU W 81973 SHEET b [1F 5 a "VW Wig v/lzi ATTORNE)PATENTEI] HAY 81973 sum 5 or s m iaf, wwwm ATTORNEK MACHINE AND METHODFOR MANIPULATING SHREDDED TOBACCO This invention relates totobacco-manipulating machines, such as continuous rod cigarette-makingmachines, in which a continuous tobacco filler is formed.

In U.S. Pat. application, Ser. No. 839,639, filed Sept. 14, I959, andnow U.S. Pat. No. 3,089,497 granted May 14, 1963, there is disclosed atobacco-manipulating machine in which a continuous filler is formed andis conveyed lengthwise on an air-pervious conveyor, air being passedthrough the filler and the conveyor to hold the filler suctionally tothe conveyor. Means are provided to detect variations in acharacteristic, (in this case, pressure drop, of the airflow through thefiller, thereby to detect variations in the air-permeability of thefiller, and the operation of a trimming device is controlled inaccordance with said variations in the characteristic to remove surplustobacco, to remove, or at least to reduce, variations of uniformitytherein.

According to the present invention, in a tobaccomanipulating machine inwhich a continuous tobacco filler is formed, such as a cigarette-makingmachine of the continuous rod type, there is provided a method intendedto improve the uniformity of the filler whlch includes the steps offeeding the filler lengthwise, trimming the filler to a desiredcross-sectional size, subjecting the filler to a sensing operation todetect variations in the mass per unit length of the filler, andutilizing the results of the sensing operation to apply compensatorypressure to the untrimmed filler to modify the degree of compacting ofthe tobacco in the filler, at least during the trimming operation, whichpressure is made greater or less according as the sensing operationindicated a less or greater quantity of tobacco passing the detectormechanism to remove, or at least, to reduce variations in averagedensity, during trimming, of the tobacco across the cross-section ofthat part of the filler to be left after trimming.

The compensatory pressure applied in this way may be effected whollyupstream of the trimming operation, or it may be carried beyond thepoint of trimming. It is preferable that the compensatory pressure is soapplied as to produce maximum compensating effect on the filler at thetime of trimming.

Further according to the present invention, there is provided a tobaccomanipulating machine in which a continuous tobacco filler is formed,such as a cigarettemaking machine of the continuous rod type, comprisingmeans to feed the filler lengthwise, a trimming device to trim thefiller to a desired cross-sectional size, sensing means to detectvariations in the mass per unit length of the filler and compensatingmeans to apply a compensatory pressure to the untrimmed filler to modifythe degree of compacting of the tobacco in the tiller, at least duringtrimming. Means are provided to adjust the compensating means inaccordance with the detected variations so that the compensatorypressure is made greater or less according as a less or greater quantityof tobacco passes the sensing means to remove, or at least, to reducevariations in average density, during trimming, of the tobacco acrossthe crosssection of that part of the filler to be left after trimming.The filler is preferably conveyed lengthwise in contact with anair-pervious conveyor, air being passed through the filler and conveyorto hold the filler thereto, suctionally.

The compensatory pressure may be air pressure which is controlled byvarying air flow through the filler and the conveyor. 7

The flow of air which is controlled to provide the compensatory pressurepasses at least through a length of filler immediately preceding thetrimming operation.

Thus the compensating means may comprise a chamber having an openingadjacent the conveyor and extending to the trimming device, means beingprovided to draw air through the chamber, the conveyor and the filler.Pressure in the chamber may be varied by a butterfly valve or a bleedvalve in the wall of the chamber.

Alternatively, the compensatory pressure may be applied to the filler bymechanical means, such as a roller, to contact the filler, and movabletowards and away from the conveyor to vary the pressure exerted on thefiller.

The compensatory pressure may be controlled by air-sensing means, suchas the means disclosed in U.S. application, Ser. No. 839,639 now U.S.Pat. No. 3,089,497, issued May 14, 1963, or may be under the control ofa nucleonic detector.

The compensatory pressure may be such as always to increase thecompacting of the filler during normal operation of the machine, i.e.,the compacting of the more compacted lengths of the filler is increasedbut to a less extent than that of the less compacted lengths.

Two embodiments of apparatus according to the invention will now bedescribed, by way of example, with reference to the accompanyingdrawings, of which:

FIG. 1 is a front elevation, partly in section, of part of a continuousrod cigarette-making machine, and shows a first embodiment of theinvention,

FIG. 2 is an enlarged view, in section, of part of FIG. 1 to showdetails of the chambers 10 and 13 of the first embodiment,

FIG. 3 is a detail view, partly in section, on line 3--3 in FIG. 2 toshow details of the first embodiment, and

FIG. 4 shows a first modification partly in section of the firstembodiment,

FIG. 5 shows a second modification partly in section, of the firstembodiment, and

FIG. 6 is a view corresponding to FIG. 1 of a second embodiment.

In the machine illustrated in FIG. 1, cut tobacco is fed into a highvelocity current of air and is impelled by the current of air to anair-pervious conveyor in the form of a perforated metal conveyor band 1which runs through the upper part of a narrow passage 2 through whichthe air flows upwardly. The tobacco so fed is suctionally held on theunderside of the conveyor band 1, on which the tobacco builds up to forma continuous filler, by means of air drawn through the tobacco and theconveyor band 1 into a suction chamber 4. The tobacco filler is carriedby the conveyor band 1 from right to left as shown in the drawingsthrough a channel open to atmosphere and comprising opposed walls 9which confine the tobacco laterally. A pipe 5, the end of which is shownin FIG. 1, extends from the suction chamber 4 to pumping means (notshown) which withdraws air from the suction chamber and maintains apressure lower than atmospheric pressure therein. Beyond the passage 2there is provided a trimming device 6 which removes surplus tobacco fromthe filler. The trimming device 6 comprises two cooperating trimmingdiscs, but only one is shown. The filler is transferred from theconveyor band 1 on to a continuous paper web 3 which forms thecontinuous paper wrapper which is folded over the trimmed filler to formthe continuous cigarette rod. The machine as so far described isdescribed more fully in, for example, US. Pat. Application Ser. No.787,954, filed Jan. 20, 1959 and now US. Pat. No. 3,088,468 granted May7, 1963.

FIGS. 1, 2 and 3 will now be referred to.

The amount of tobacco which is removed from the filler is varied inaccordance with variations in the air permeability of the filler. Asensing chamber 10 is pro vided above the conveyor band 1 and has anopening 1 1 which is in communication with a short length of theconveyor band of less than a cigarette length. A pipe 12 extends fromthe chamber 10 into the pipe 5 so that air is drawn through the filler,the conveyor band and the chamber. Thus, depending on the airpermeability of the length of filler at any instant below the chamber10, the pressure in chamber will be varied and these variations providean indication of variations in uniformity of the filler along itslength.

For the purposes of the present explanation, the trimming device 6 willbe considered to be fixed in position relative to the conveyor band 1when the filler will be trimmed to a constant cross-sectional areadelineated by the discs of the trimming device, the walls 9 and theband 1. If the average density of the tobacco across thiscross-sectional area remained constant as the filler moved past thetrimming device the mass per unit length of the trimmed filler would, ofnecessity, also be constant. It is found, however, that if the effect ofsuction on the filler is considered, there will be a greater flow of airthrough a given length of filler stream containing relatively littletobacco than through a similar length containing a relatively largequantity of tobacco and thus there will be a smaller pressure drop i.e.,a higher pressure in chamber 10, in the first case than in the secondcase.

The degree of compacting of the tobacco, and therefore the averagedensity of the tobacco, between the level at which the trimming deviceoperates and the conveyor band 1 is dependent on the pressure dropacross the untrimmed filler stream, an increase in pressure dropproducing a greater degree of compacting, and a greater average density,and vice versa. The mass per unit length of the trimmed filler will begreater where the tobacco has been subjected to a greater degree ofcompacting and thus the mass per unit length of the trimmed fillerdepends on the pressure drop which has been applied to the untrimmedfiller stream. As the applied pressure drop depends on the quantity oftobacco in the untrimmed filler stream the mass per unit length of thetrimmed filler will vary in the same sense as the mass per unit lengthof the untrimmed filler stream.

However, it is found that the variations in mass per unit length of thetrimmed filler are smaller than the corresponding variations of theuntrimmed filler stream, and also that the variations of the untrimmedfiller stream are a smaller proportion of the mean weight of that streamthan the variations of the trimmed filler are of the mean weight of thetrimmed filler.

To avoid, or at least to reduce, these residual variations in thetrimmed filler, compensator means are provided to modify the degree ofcompacting of the tobacco in the filler as it is operated on by thetrimming device to remove, or at least to reduce, variations in thecompacting and therefore in the average density of the portion of thefiller between the level at which the trimming device 6 operates and theconveyor band 1.

The compensator means comprises a chamber 13, which may conveniently besimilar to the chamber 10. This chamber 13 has an opening 14 in itsunderside which communicates with the conveyor band 1. The chamber 13 issituated downstream of the chamber 10. The downstream end of the chamber13 is situated directly above the position at which the filler firstcontacts the trimming device.

A pipe 15 extends from the chamber 13 to a separate fan 16 whichoperates to draw air through the filler, the conveyor band 1 and thechamber 13. Pressure-varying means in the form of a throttle valve 17 isprovided in the chamber 13, the throttle valve being of the butterflytype and aerodynamically balanced so that there is little or no netturning moment on the valve due to air flowing through the chamber 13.The spindle 18 of the valve 17 carries a bevel gear 24 which meshes witha similar gear 25 carried on a spindle 26 which has a thread of longpitch which cooperates with a similar thread in the bore of a nut member19 carried by one end of a resilient bellows 20 secured to a bracket 27outside the suction chamber 4. A pair of collars 28 are provided on thespindle 26, one on each side of the wall of the suction chamber 4 toprevent axial movement of the spindle.

The pressure within the chamber 10 is communicated to the interior ofthe bellows 20 by means of a pipe 21. The chamber 10 is spaced from thechamber 13 so that the time interval between a pressure variationoccurring in the chamber 10 and a corresponding rotation of valve 17 isthe same as the time taken" by the filler to travel from beneath thecentre of the chamber 10 to beneath the downstream end of chamber 13.

The nut member 19 has a projection 22 which is slidable in anaxially-extending slot in a guide 23 carried by the suction chamber 4.

Thus, variations in pressure in the chamber 10 cause the bellows 20 toexpand or contract and move the nut member 19 along the spindle 26 thuscausing it to rotate, and through the bevel gears 24, 25, to rotate thevalve 17.

The manner of operation of the chambers 10 and 13 is as follows. As thefiller passes under the chamber 10 variations in air pressure will occurtherein due to variations in air permeability of the filler, arisingfrom variations in the mass per unit length of the filler. As mentionedabove, these variations in permeability result in a greater pressuredrop occurring across lengths of the filler having a relatively largemass per unit length, thus causing a greater degree of compacting of thetobacco in the filler, so that the trimmed filler would be morecompacted and dense along these lengths than in the case of lengths offiller having a relatively small mass per unit length. When a lengthhaving a relatively large mass per unit length is under the chamber 10,a lower pressure is present in that chamber, and the bellows 20contracts. The nut member 19 turns the spindle 26 and the throttle valve17 rotates to a position in which it provides a greater restriction toflow through the chamber 13 when that same length of filler is below thechamber 13. A higher pressure is thus produced between the throttlevalve 17 and the band 1 and consequently there is a smaller pressuredrop across the tiller under the chamber 13. This allows the filler toexpand downward slightly, thus reducing the degree of compacting of thelayers of tobacco in the tiller and reducing the average density of thetobacco in the filler as it reaches the trimming device 6. With a lengthof filler having a relatively low mass per unit length the oppositeoccurs. Therefore variations in the compacting and average density ofthe filler as it is trimmed are avoided, or at least are reduced, and amore uniform filler results.

As a little time is necessary for the tobacco in the filler to adjustitself to any different pressure drop to which it is subjected under thechamber 13 the slot 14 must be of sufficient length for the tobacco inthe filler to respond to the controlled air flow through it.

The trimming device has been considered as being fixed relative to theconveyor band 1 but, inaddition, apparatus is provided downstream of thetrimming device 6 to provide a check on the mean mass per unit length ofthe filler, and the trimming device is moved towards or away from theconveyor band 1 in response to variations in the mean mass per unitlength of the filler to provide a correction for such variations. Thesevariations are detected by scanning apparatus utilizing a source of betaradiation. Such apparatus is disclosed, for example, in US. application,Ser. No. 839,639, now Pat. No. 3,089,497, and is indicateddiagrammatically in FIG. 1.

The trimming device 6 is supported by a link 50 pivotally connected to alever 51 pivotally mounted in stationary structure at its right hand end52. At its left hand end the lever 51 carries a nut member 53 in whichis threaded a screwed member 54 on which is provided a wormwheel 55.Rotation of the wormwheel 55 in one direction or the other thus raisesand lowers the left hand end of the lever 51, and with it the trimmingdevice 6, so varying the cross-sectional area of filler between the sidewalls 9, conveyor band 1 and the trimming discs 6. The wormwheel isrotated by a worm 56 carried on the spindle of a reversible electricmotor 57. A source of penetrative radiation such as Strontium 90 isindicated at 58. This is positioned adjacent the wrapped cigarette rodmade on the machine, a length of which is indicated at C and, on theother side of the cigarette rod is an ionisation chamber 59. A similarsource and ionisation chamber are shown at 60 and 61 respectively, butwith a standard metal screen 62 interposed between them which has a rayabsorption equal to that of the desired mass of the cigarette rod. Itwill be appreciated that the cigarette rod is the trimmed filler with apaper wrapper and its mass per unit length is therefore substantiallythe same as the trimmed filler. The outputs of the two ionisationchambers 59 and 61 are arranged electrically in opposition and theresultant current is the difference of the two inputs, and its directiondepends on whether the cigarette rod is lighter or heavier than desired.The resultant current is fed to an amplifier 63, the output of whichdrives the electric motor. Thus, if the mean mass per unit length of thecigarette rod, and thus of the trimmed filler, is too low the electricmotor 57 rotates to lower the trimming discs 6 away from the conveyor 1and thus increase the cross-sectional area of the trimmed filler betweenthe trimming discs and the conveyor.

In the modification shown in FIG. 4 the pressurevarying means for thecompensator chamber 13 comprises, in place of the throttle valve 17, aneedle valve to admit a flow of air from atmosphere into the chamber 13which by-passes the tobacco filler. A pipe 29 extends from the chamber13 through the wall of the suction chamber 4 so that its other end isopen to atmosphere and also constitutes the seat 30 of the needle valve.A rod 31 extends from the bellows 20 and carries a profiled needle valvemember 32 which protrudes into the orifice and varies its effectivearea. Thus, as the pressure in chamber 10 increases, the bellows 20expands, moving the valve member 32 into the orifice 30 to decrease itseffective area, and thus the amount of air drawn into the chamber 13 bythe fan 16, so that the pressure in chamber 13 falls, and the pressuredrop across the tobacco filler under the chamber 13 increases. If thepressure in chamber 10 decreases, the opposite effect occurs.

Apparatus measuring the mean mass per unit length of the trimmed fillercould also be made to adjust a needle valve such as valve 32 instead ofraising and lowering the trimming device 6. Thus, as shown in FIG. 5,the spindle of the reversible electric motor 57 shown in FIG. 1, insteadof driving the worm 56 and wormwheel 55, carries an internally threadednut member which receives the threaded end of a rod 71. The rod 71carries a profiled needle valve member 72, similar to the valve member32, and this protrudes into a seat 73 in the wall of the chamber 13,similar to the seat 30. Rotation of the rod 71 is prevented by anyconventional means. The motor 57 is restrained from rotation by beingcarried by a bracket 74 secured to the chamber 13. Rotation of thespindle of the motor 57 thus moves the valve member 72 into or out ofthe seat 73 depending on whether the cigarette rod, and thus the trimmedfiller, is light or heavy.

This arrangement may be in addition to the valves shown in FIGS. 3 or 4or may be the sole control for varying the air pressure in the chamber13, and thus the compensatory pressure. In the latter case, of course,the sensing chamber 10 and bellows 20 would not be provided.

A separate fan, such as fan 16, need not be used to withdraw air fromthe compensator chamber 13. Thus the pipe 15 could be led into pipe 5,as with the pipe 12 from the sensing chamber 10. However, if a differentdatum for the pressure in chamber 13 compared with that in chamber 10 isdesired, this is more easily ob tained by using a separate fan. Forexample, it may be desired that there should be a lower datum for thepressure in the compensator chamber 13. Thus the pressure drop acrossthe filler under the chamber 13 may always be such as to increase thecompactness of the filler. Then, if the pressure drop across the fillerunder chamber 10 decreases, the pressure drop across the filler underchamber 13 will increase to increase the degree of compacting of thefiller; if the pressure drop across the filler under the chamber 10increases, the pressure drop produced by chamber 13 will decrease,

but will still be such as to increase the degree of compacting of thelayers of tobacco in the filler, but to a lesser extent.

In the second embodiment of the invention illustrated in FIG. 6 thecompensatory pressure is applied by mechanical means. In this embodimentthe chamber 13 is replaced by a roller 80 which is pivotally mounted onthe end of an arm 81 which is pivotally mounted at its other end on theshaft 82 carrying the sealing device 83. The sealing device 83 is nopart of the present invention but is fully described in U.S. Appln.,Ser. No. 856,131 filed Nov. 30, 1959 and now U.S. Pat. No. 3,091,244granted May 28, 1963. The roller 80 runs in contact with the lowersurface of the untrimmed tobacco filler and is movable towards and awayfrom the conveyor l to vary the compensatory pressure applied to thefiller by raising and lowering of the arm 81. To effect such movement ofthe arm 81, a rod 84 has its lower and hooked end pivotally connected tothe arm 81 adjacent the roller. The upper end of the rod 84 is connectedto the output member 85 of a hydraulic servo device indicated generallyat 86. Such a servo device is described fully in, for example, US.application Ser. No. 839,639, now Pat. No. 3,089,497. The input memberof the servo device is indicated at 87, and is operated by a pivotedlever 88, which in turn is operated by the free end of a bellows 89,which may be identical with the bellows 20 shown in FIG. 3. A sensingchamber 90, identical with chamber of FIGS. 1 and 2, is provided andperforms identical functions. Pressure variations in the chamber 90 arecommunicated to the bellows 89 by a pipe 91. Thus expansion andcontraction of the bellows 89 in response to varying pressures in thechamber 90 result in raising and lowering of the roller 80 to apply avarying compensatory pressure to the filler and modify its compacting toremove, or at least to reduce, variations in the average density of theportion of the tobacco filler between the trimming device 6 and the band1.

As with the construction of FIG. 1 the trimming device 6 is raised andlowered under control of a nucleonic sensing device as described withreference to FIG. 1.

To assist the tobacco filler to reach its modified degree of compactingunder control of the compensating means described, it may be necessaryfor the side walls 9 to be inclined at an angle less than a right angleto the conveyor band 1. This is shown in FIGS. 3, 4 and 5.

What I claim as my invention and desire to secure by Letters Patent is:

1. In an industrial processing system using compressible material toform a product and including a conveyor for said material, and means forfeeding an amount of said material to said conveyor in excess of thatrequired to form the product, the material on said conveyor having afree surface, a control system for controlling the quantity of saidmaterial used in forming said product, said control system comprisingseparating means for separating said material into a first portion ofpredetermined cross section and a second portion containing the excess,adjustable means for pressing the free surface of said material with apressure exceeding atmospheric pressure toward said conveyor ahead ofsaid separating means thereby controlling the density of said materialas conveyed to said separating means, means for feeding said separatedfirst portion to form said product, detecting means for detecting thequantity of said material in said product, and means responsive to saiddetecting means for controlling said adjustable means in accordance withthe quantity of said material detected to maintain said quantityconstant.

2. A machine for producing a tobacco rod containing a predeterminedquantity of tobacco per unit length thereof, comprising conveyor meansdefining an elongated path and having an elongated groove which definesa first portion of said path; means for feeding a mass of tobacco intosaid path in such quantities that the tobacco forms a moving streamhaving an exposed side and containing tobacco in excess of that requiredin the tobacco rod; trimming means adjacent to said groove for removingexcess tobacco from the stream whereby the remainder of the stream formsa tobacco rod; compacting means located upstream of and in closeproximity to said trimming means, said compacting means includingbiasing means arranged to subject the exposed side of the stream to theaction of a mechanical compacting force acting in a direction transverseto the direction of movement of the tobacco stream, said compactingmeans being adjustable; testing means adjacent to a second portion ofsaid path for measuring the quantity of tobacco per unit length of themass of tobacco moving in said second portion of the path; and adjustingmeans operatively connected with said testing means for adjusting saidbiasing means so as to reduce the compacting force of said biasing meanswhen the measured quantity exceeds said predetermined quantity and toincrease the compacting force of said biasing means when the measuredquantity is less than said predetermined quantity.

3. A machine for producing a tobacco rod containing a predeterminedquantity of tobacco per unit length thereof, comprising conveyor meansdefining an elongated path and having an elongated groove which definesa first portion of said path; means for feeding a mass of tobacco intosaid path in such quantities that the tobacco forms a moving streamhaving an exposed side and containing tobacco in excess of that requiredin the tobacco rod; trimming means adjacent to said groove for removingexcess tobacco from the stream whereby the remainder of the stream formsa tobacco rod; compacting means located upstream of and in closeproximity to said trimming means, said compact-l ing means includingbiasing means arranged to subject the exposed side of the stream to theaction of a mechanical compacting force acting in a direction transverseto the direction of movement of the tobacco stream, said compactingmeans being adjustable; testing means adjacent to a second portion ofsaid path for measuring the quantity of tobacco per unit length of themass of tobacco moving in said second portion of the path; adjustingmeans operatively connected with said testing means for adjusting saidbiasing means so as to reduce the compacting force of said biasing meanswhen the measured quantity exceeds said predetermined quantity and toincrease the compacting force of said biasing means when the measuredquantity is less than said predetermined quantity; and wrapping meanslocated downstream of said trimming means for applying a continuouswrapper around the tobacco rod and for thus transforming the tobacco rodinto a wrapped tobacco rod, said testing means being located downstreamof said trimming means for measuring the quantity tobacco per unitlength of the tobacco rod.

4. A method of producing a wrapped tobacco rod which contains apredetermined quantity of tobacco per unit length thereof, comprisingthe steps of forming a tobacco stream having an exposed side andcontaining tobacco in excess of that required in the tobacco rod; movingthe stream in a predetermined path; compacting the stream by subjectingsaid exposed side to the action of a mechanical compacting force actingin a direction transverse to the direction of movement of the stream;trimming the thus compacted stream by removing excess tobacco along saidexposed side of the stream whereby the remainder of the stream forms atobacco rod; wrapping said tobacco rod into a continu ously suppliedwrapper to form a wrapped tobacco rod; measuring the quantity of tobaccoper unit length of the tobacco rod; and adjusting the compacting forcein accordance with the measured result by reducing the compacting forcewhen the measured quantity exceeds said predetermined quantity and byincreasing the compacting force when the measured quantity is less thansaid predetermined quantity.

1. In an industrial processing system using compressible material toform a product and including a conveyor for said material, and means forfeeding an amount of said material to said conveyor in excess of thatrequired to form the product, the material on said conveyor having afree surface, a control system for controlling the quantity of saidmaterial used in forming said product, said control system comprisingseparating means for separating said material into a first portion ofpredetermined cross section and a second portion containing the excess,adjustable means for pressing the free surface of said material with apressure exceeding atmospheric pressure toward said conveyor ahead ofsaid separating means thereby controlling the density of said materialas conveyed to said separating means, means for feeding said separatedfirst portion to form said product, detecting means for detecting thequantity of said material in said product, and means responsive to saiddetecting means for controlling said adjustable means in accordance withthe quantity of said material detected to maintain said quantityconstant.
 2. A machine for producing a tobacco rod containing apredetermined quantity of tobacco per unit length thereof, comprisingconveyor means defining an elongated path and having an elongated groovewhich defines a first portion of said path; means for feeding a mass oftobacco into said path in such quantities that the tobacco forms amoving stream having an exposed side and containing tobacco in excess ofthat required in the tobacco rod; trimming means adjacent to said groovefor removing excess tobacco from the stream whereby the remainder of thestream forms a tobacco rod; compacting means located upstream of and inclose proximity to said trimming means, said compacting means includingbiasing means arranged to subject the exposed side of the stream to theaction of a mechanical compacting force acting in a direction transverseto the direction of movement of the tobacco stream, said compactingmeans being adjustable; testing means adjacent to a second portion ofsaid path for measuring the quantity of tobacco per unit length of themass of tobacco moving in said second portion of the path; and adjustingmeans operatively connected with said testing means for adjusting saidbiasing means so as to reduce the compacting force of said biasing meanswhen the measured quantity exceeds said predetermined quantity and toincrease the compacting force of said biasing means when the measuredquantity is less than said predetermined quantity.
 3. A machine forproducing a tobacco rod containing a predetermined quantity of tobaccoper unit length thereof, comprising conveyor means defining an elongatedpath and having an elongated groove which defines a first portion ofsaid path; means for feeding a mass of tobacco into said path in suchquantities that the tobacco forms a moving stream having an exposed sideand containing tobacco in excess of that required in the tobacco rod;trimming means adjacent to said groove for removing excess tobacco fromthe stream whereby the remainder of the stream forms a tobacco rod;compactiNg means located upstream of and in close proximity to saidtrimming means, said compacting means including biasing means arrangedto subject the exposed side of the stream to the action of a mechanicalcompacting force acting in a direction transverse to the direction ofmovement of the tobacco stream, said compacting means being adjustable;testing means adjacent to a second portion of said path for measuringthe quantity of tobacco per unit length of the mass of tobacco moving insaid second portion of the path; adjusting means operatively connectedwith said testing means for adjusting said biasing means so as to reducethe compacting force of said biasing means when the measured quantityexceeds said predetermined quantity and to increase the compacting forceof said biasing means when the measured quantity is less than saidpredetermined quantity; and wrapping means located downstream of saidtrimming means for applying a continuous wrapper around the tobacco rodand for thus transforming the tobacco rod into a wrapped tobacco rod,said testing means being located downstream of said trimming means formeasuring the quantity tobacco per unit length of the tobacco rod.
 4. Amethod of producing a wrapped tobacco rod which contains a predeterminedquantity of tobacco per unit length thereof, comprising the steps offorming a tobacco stream having an exposed side and containing tobaccoin excess of that required in the tobacco rod; moving the stream in apredetermined path; compacting the stream by subjecting said exposedside to the action of a mechanical compacting force acting in adirection transverse to the direction of movement of the stream;trimming the thus compacted stream by removing excess tobacco along saidexposed side of the stream whereby the remainder of the stream forms atobacco rod; wrapping said tobacco rod into a continuously suppliedwrapper to form a wrapped tobacco rod; measuring the quantity of tobaccoper unit length of the tobacco rod; and adjusting the compacting forcein accordance with the measured result by reducing the compacting forcewhen the measured quantity exceeds said predetermined quantity and byincreasing the compacting force when the measured quantity is less thansaid predetermined quantity.